Road contraction joint



Feb. 7, 1939. R. R. RoBERTsoN ROAD CONTRACTION JOINT 2 Sheets-Sheet l f Filed Aug. 19, 1957 I Feb.` 7, 1939.l R. R. ROBERTSON .2,145,951

ROAD CONTRACTION JOI'NT 'Filed Aug-19, 1937 2 sheets-sneer 2 Patented Feb. 7, 1939 PAT ENT OFFICE ROAD CONTRACTION JOINT RobertR. Robertson, Chicago, Ill., assigner to The Translode `Joint Company, Chicago Heights, Ill., a corporation of Illinois Application August 19, 1937,1Serial No. 159,830

f 10 Claims.

This vinvention relates to-a road joint, and more particularly to a load transmission contraction joint adapted to be positioned to extend transversely across the r-oadway, and is made up of a plurality of reversed, staggered load transmission contraction units or spaced aligned units adapted to be staked in position upon the road sub-grade and having the upper ends connected,

before the pouring of -concrete, by means of a removable edging bar or by means of a cracking plate 'Y and cap, either of which is continuous across the roadway; said bar or cap being removabl'e'after the rst pass of the screed Aor tamping machine to permit edging of the concrete road lcaslabs and the formation of a top groove rfor the reception of a plastic ller such as asphalt or the like. v It-vis an robject of this invention to provide a load transmission contraction joint consisting 202 of a plurality of reversed, staggered loadtransymitting units, ynormally connected by means of a removable edging bar.r

jIt is a Yfurther object of this invention to provide a contraction joint comprising spaced, zraligned load transmissi-on units connected by a cracking plate having a removable edging cap engaged thereon.

It is also an object of this invention to provide a contraction joint consisting of a plurality 30;of spaced aligned contraction u nits which are connected by means of a cracking plate having an edging cap removably supported thereon before the pouring of concrete; said units and cracking plate adapted to be left embedded in 35zthe concrete, when the edging cap is removed to permit edging of the concrete slabs and the lling of the groove formed by the ,removal of said edging cap.L

It is an important object of this invention to provide a road contraction joint adapted to extend transversely of a roadway and consisting of a plurality of load transmitting contraction units which in one form of the device lmay be spaced apart and reversed in staggered relation to one another, or which in another form may be spaced apart and aligned Without being reversed; said units adapted to be held in position on the road subi-grade by -means of stakes or `50 vthe like. VThe contraction units are normally y mslabs, and furthermore permit -a plastic filling to be deposited in the groove formed by the removal of the edging bar or cap.

Other and further objects of this invention will be apparent from the disclosures in the speciiicatio'n'and the accompanying drawings.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

VOn the drawings:

Figure 1 is a fragmentary top plan view of a road contraction joint forming mechanism embodying the principles of this invention and showing the staggered arrangement of the contraction units with respect to the removable edging bar before the pouring of concrete to form the road slabs.

Figure 2 is an 'enlarged fragmentary isometric view of one of the contraction units associated with a fragmentary portion of the removable edging bar.

Figure 3 isan enlarged vertical transverse section taken on line III-III of Figure 1.

Figure 4 is a fragmentary top plan view of a modified form of road contraction joint forming 'mechanism in which the load transmission units are arranged in spaced, aligned relationship with respect to one another instead of being reversed or staggered as shown in Figure l.

Figure 5 is an enlarged fragmentary side elevational view of the contraction joint forming mechanism shown in Figure 4 and illustrating the cracking plate for connecting theload transmission units withsaid cracking plate having an edging cap removably engaged thereon.

Figure 6 is an enlarged transverse detail section taken on line VI-VI of Figure 5.

Figure 7 is an enlarged fragmentary vertical detail section taken through the upper portion of the joint forming mechanism after the same khas been embedded in concrete and after the spaceabove the joint has been closed by a plastic filling.

Figure 8 illustrates a fragmentaryv top plan view of still another modified form oi contraction joint forming 'mechanism wherein the load transmission units are reversed and staggered with respect toone another and are connected in their spaced relation by means of a cracking plate'and a removable edging cap similar to the arrangement illustrated in Figure 5.

As shown on the drawings:

This invention relates to a transverse joint for roads andmore particularly to a load transmission contraction joint yforming mechanism adapted to be supported ron the road sub-grade,

to extend across the roadway. The contraction joint forming mechanism consists of a plurality of alternately reversed and staggered load transmission contraction units which are temporarily connected before the pouring of the concrete, by a removable edging bar.

Each of the load transmission contraction units comprises a lower section and an upper section which slidably intert with one another. rlhe lower section comprises an upright body plate I, constructed of sheet metal, and havingY integrally formed on the lower edge thereof at substantially right angles, a base plate or foot 2 provided with an opening or aperture 3 forthe recention of the lower tapered end of a stake 4. The base plate 2 has a portion thereof cut out and bent downwardly and rearwardly to lie in substantially the plane of the base plate 2 but projecting from the opposite side of the body plate I in the form of a brace plate 5 as clearly illustrated in Figure 2. substantially right angles to the upper margin of the body plate I, is a connecting plate or flange 5, the outer margin of which integrally connects up with a round, split anchoring sleeve or tube l. Positioned parallel to the connecting plate or iange 6 and integral with the split anchoring sleeve 'I is a load transmitting plate 8 which is positioned to project across ther plane of the body plate I and through the vertical plane of the joint. As clearly illustrated in Figure 3 the load transmission plate 8 is wider than'the connecting plate 6. As shownin Figure 3 the upper portion of the retaining stake V4 is provided with an Varm or hook member 9 which is adapted to fit over the anchoring sleeve or tube'l for holding the lower section of the load transmissionunit staked in position upon 'the road sub-grade to hold the unit in position during the pouring of concrete, for the formation Vof concrete road slabs on opposite sides of the contraction joint unit, Y

Interiitting with the lower section of the contraction joint unit, is an upper section comprising an upper body plate IIJ having integrally formed at substantially right angles to the lower margin thereof, a connecting plate or flange II the bottom surface of which is in frictional engagement with the top surface of the load transmission plate 8 of the lower section of the joint unit. Integrally formed on the outer margin of the connecting plate II, is a split anchoring sleeve or tube I 2. Positioned parallel to the connecting plate II and integral with the split anchoring sleeve I2 is a load transmitting plate I3 which is also positioned to project across the plane of the body plate I0 and the lower body plate I into frictional sliding contact with the lower surface of the load transmitting plate 8 of the lower section of the joint unit. The two overlapping plates 8 and I3 separate the upper body plate I0 from the lower body plate I with the wide load transmitting plate of one sectionslidablytting between the two plates of the other section.

The improved contraction joint units are arranged in reversed spaced staggered relation, as illustrated in Figure 1, across the roadway and are staked or otherwise integrally secured to the road sub-grade to hold the units in proper position.

The body plates I0 of the upper sections of the contraction joint units are connected one to another by means of a removable edging bar I4. Rigidly secured in staggered relation on opposite sides of the edging bar I4 are a plurality of metal Integrally formed at upper side portions of each top body plate IU '5 may be bevelledk at I6 to facilitate engagement of the edging bar socket on said body plate. V` Struck inwardly from the socket portionV I5 of each strip I8 is a spring retaining lip or tongue I1 adapted to spring into tightk frictional engage- Y10 Y `ment with the top body plate I0, Yas clearly' illustrated in Figure 3, to hold the removable edging bar supported in position for connecting l the staggered contraction joint units.

' With the contraction joint units arranged in 15 reversed staggered relation across the roadway and secured in position by means of the stakes Y4 or the like and with the edging bar I4 removably engaged on the upper ends of the upper body plates Ill, concrete is poured on opposite Vsides 20 of the joint forming mechanism to form road slabs. The concrete which forms the roadslabs,. embeds the transverse portions of the road joint units and the load transmission or anchoring part thereof, so that 25y sleeves 'I and I2 forming a the upper and lower sections of each unit are., Y

anchored in the road slabs on opposite sides of the joint forming mechanisms.V After the completion of the pouring of the concreterand after the first pass of the screed or tamper for levelling 30VV` the top surface of the concrete, the edging bar I4 is lifted off of the upper end of the top body plates II) and is removed from-the concreteleav.-

ing a transverse-groove across the roadway. By the use of proper edging tools the upper edges of the concrete slabs, formed on opposite sidesof the joint forming mechanisms, are `properly edged A and the groove is then filled with a plasticller such as asphalt or the like.

The improved road contraction mechanisms of this invention afford an arrrangerment whereby the amount of sheet metal required for the formingy of the-joint is materially rejoint forming ,40'

duced in view of the fact that theV staggered units are comparatively short and are spaced 45* apart thereby requiring less material than in the case of acontraction joint which is continuous across the roadway. The edging bar I4, which is removably engaged on the upper ends of the contraction'joint units, may be repeatedly reused -50' thereby affording an additional saving.

After a contraction joint mechanism has been supported on a road sub-grade transversely of the roadway andfis embedded between concrete, Ythe edging bar I4 is removed after which the edges of the concrete slabs are rounded or nishedoif and the groove left by the removal of the-edging bar is then filled with a plastic material to seal the top of the joint. The construction affords an arrangement whereby the concrete opposite sides of the joint are connected one with the other at spaced intervals by the contraction joint units, the sections forming the same being Y anchored in the adjacent road slabs. This arslabs on 60 rangement permits loads which are applied to a 65 road slab on one Vside ofthe joint to be transmitted through the joint unit to the road slab on the opposite side of the joint. With the contraction of the road slabs, the interttingl por-` tions of the upper and lower sections of each of 70" the joint units move outwardly with respect to one another to widen the middle portion of the joint with the separation of the road slabs. j

Figures Llfto 7 inclusive illustrate a modified form'h of roadcontraction joint which consists of 75 apluralityof spaced andaligned load transmission contraction units,which as clearly illustrated inFigurefl are supported on a road sub-grade transversely of the roadwith all of the units facing the same direction and disposed in a straight row in spaced parallel -relation with respect to one another.

The ,group of load transmission contraction units are of substantially the samey construction as the units illustrated in Figures l to 3 inclusive.

In the modied form of the joint forming mechanism illustrated in Figures 4 to 7 inclusive, each of the load transmission units is constructed identically to the units illustrated in Figure 3, and like parts are, therefore, indicated by corresponding reference numerals. The contraction units in the modified form of the construction are also retained in position by means of stakes 4.

The ,body plates I of the uppersections of the contraction joint units are connected one to another by means of a cracking plate I9-constructed of metal, fiber or other suitable material. The

cracking plate I9 has struck from the upper marginal portion thereof ,a plurality of spaced hangers or hooks `2l) all of which project from one side ofthe cracking plate I9 and are engaged over the upper marginal edges of the body plates II] ofthe top sections of the contraction joint units.

, The hook memloersl 20 are so formed that the cracking plate I9 isk securely held in position connecting the aligned contraction joint units. In case-itgis 'desired to rigidly connect the cracking plate I9 with the body plates I9 of the spaced units, said cracking plate I9 may be spot-welded to the plates IIJ or otherwise rigidly fastened thereto.

For the purpose of permitting proper edging of the upper corners of the concrete road slabs between which the joint forming mechanism is embedded, a U-cross sectioned or inverted channel edging cap 2I is removably engaged over the upper edges of the cracking plate I9 and the body plates I0 of the separate units.

With the contraction joint units arranged in aligned relationship across the roadway and secured in position by means of stakes 4 or the like, and with the cracking plate I9 connecting the units and supporting thev removable edging cap 2l in place as illustrated in Figure 6, concrete is poured on opposite sides of the joint forming mechanisms to form the road slabs 22 and 23 (Figure 7). The concrete which forms the road slabs, embeds the transverse portions of the road joint units so that the upper sections of the units yare anchored in the road slab 22, while the lower sections of the units are anchored in the road slab 23. After the completion of the pouring of the concrete and after the first pass of the screed or tamper for levelling the top surface of the concrete, the edging cap 2| is lifted ofi' of the upper edge of the cracking plate I9 to leave a top groove in the concrete permitting proper edging of the upper corners of the road slabs. After the edging of the slabs, the top groove of the joint is iilled with a plastic filler such as asphalt or the like to form a top ller or seal 24 to embed the upper margins of the body plates Ill and thek edging cap,2I is removable after the pouring of' concrete'to form a top groove for the reception of a llerl of plastic material for sealing the top ofthe joint.

It will of course be understood that various details of construction may be varied through a wide range without departing from the principles of this invention, and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I'claim as my invention:

1. A contraction joint forming mechanism comprising a plurality of reversed, staggered load transmission units, each comprising slidably interiitting sections, means for securing the units in position during the pouring of concrete, a continuous edging bar, socket members on the edging, bar for engagement with the upper ends of the load transmission units, and latching means forming a part of the socket members and frictionally engaging the upper portions of the load transmission units for supporting the edging bar in position until after the pouring of concrete to form road slabs on opposite sides of the joint forming mechanism.

2. A load transmitting device for forming a contraction joint between concrete road slabs, said device comprising a plurality of reversed, staggered load transmission units, each embedded inv the concrete road slabs at opposite sides of the joint,.and each of said units comprising reversed intertting sections each formed with plate members disposed transversely of the joint with the plate members positioned in slidable overlapping engagement with one another, a continuous edging bar, socket members secured on opposite sides thereof for removable engagement over the upper ends of said load transmission units, and resilient means struck from the socket members and having resilient engagement with the upper portions of said units for releasably holding the edging bar in position and connecting the load transmission units one with the other.

3. A load transmission contraction joint forming mechanism for embedding between adjacent concrete road slabs, said joint forming mechanism comprising a plurality of separated load transmitting units, each constructed of a top section and a bottom section adjustably intertting one another, each of said sections comprising a straight plate, an angled plate and a split sleeve integrally connecting said plates with the straight plate of one section projecting between the straight plate and the angle plate of the other section, a base plate integrally formed on each or said lower sections for positioning beneath one of the road slabs, and means struck from the base plate and projecting beneath the opposite road slab.

4. A load transmission contraction joint forming mechanism for embedding between adjacent concrete road slabs and comprising a plurality of separated load transmitting devices, each of said devices constructed of intertting adjustable sections, each section consisting of a straight plate, an angled plate and a split sleeve integrally connecting said plates, one section orf each of said devices having a base plate formed thereon and projecting beneath one of the road slabs, and a member struck from the base plate and projecting across the joint beneath the opposite road slab.

5. A load transmission contraction joint formand the other base member projecting across the f rating concrete road slabs, said mechanism comprising a plurality of load transmitting units, with each unit comprising an upper section and a lower section slidably interfitting therewith, an apertured base plate integrally formed on the lower section and projecting beneath one of the road slabs, and a member struck from the base plate and directed across the joint beneath the opposite road slab. l

6. In a concrete construction, a load transmitting joint forming mechanism embedded between adjacent concrete road slabs, said mechanism comprising a plurality of separated load transmitting units each consisting of reversed slidably intertting upper and lower sections, each section including a pair of plates integrallyconnected by a bight portion, with a plate of oneV section slidably projecting between and in frictional Contact with both of the plates oaf the other section, and base members formed on each of said lower Vsections with one of said base members projecting beneath one of said road slabs jointbeneath the adjacent road slab.

7. A contraction joint forming mechanism including in combination a plurality of spaced load transmission contraction units and means for connecting the same in spaced relation to one another, said means comprising a continuous bar member, sockets formed on the sides thereof, and resilient l'atching means forming part of the sockets for releasable engagement with the contraction units.

f 8. A road joint former comprising a plurality of load transmission units aligned in spaced, Staggered relation with respect to one another, and means for connecting said units, said means comprising'a continuous bar, socket members alternatelyform'ed on'opposite sides thereof for en- .Y

gagement with the load transmission units, and resilient means struck inwardly from said sockets for frictional engagement with the loadl transmission units to hold said edging bar detachably engaged in position. Y

9. Ar joint forming 'mechanism including Vin combination a plurality of load transmission units arranged in spaced, parallel relation with respect to one another, a, cracking plate connecting said units, means struck from said cracking plate for supporting the cracking plate on said units, and an edging means supported on the-cracking plate to enclose said means and also'connecting said units.

10. Aroad joint forming mechanism comprising a pluralityod:` load transmission units, means for supporting the units in spaced, parallel relation on a road sub-grade, a cracking plate connectingall of said units, hook members on said ROBERT R. ROBERTSON. 

